Pulverizing mill



Mar. 27, 1923.

' R. E. H. POMEROY,

PULVERIZING MILL.

FILED JULY l0, 1922.

4 SHEETS-SHEET l R. E. H. POMEROY.

PULVERIZING MILL.

FILED 1u1Y1o.1922. 4 SHEETS-SHEET 2.

Mar. 27, 1923. 1,449,441.

Mar. 27, 1923. 1,449,441..

R. E. H. P0MER0Y.

PULVERIZING MILL.

FILED JULY I0, 1922. 4 SHEETS-SHEET 3.

w Q R Q S I N m Q /NVEHTa/e'- TTQPNEY the reducing chamber is preferably induced' Patented Mar. 27, 1923-..

UNITED STATES PATENT OFFICE..

RALPH E. H. PMEROY, OF CANTON, OHIO.

PULVERIZING MILL.

Application led July 10,

To all whom t may concern,.-

Be it known that I, RALPH POME- RoY, residing at Canton, in the county of Stark and btate of Ohio, a citizen of the United States, have invented or discovered certain new and useful Improvements in Pulverizing Mills, of which improvements the following is a specification.

In prior applications, to-wit: Serial Numbers 393,147, filed June 30, 1920; 474,079, filed June 1, 1921; 516,380 tiled November 19,1921; 522,360, filed December 14., 1921; and 539,417, tiled February 27, 1922, are described and claimed improvements in the method of and apparatus for causing the permeation of currents of air through a charge or mass consisting of pieces of frangible material and objects formed of more .durable material such as metal balls for the purpose of removing reduced particles from the zone of reduction. The means described and shown lin said applications for directing the currents or streams of air into the charge or mass consist of a shell having perforated perimeter revoluble in a. closed casing having an opening therethrough for the admission of air which passes into and through the charge in the shell, as perforations in the shell are brought into line with said opening. As in such aconstruction the formation of and maintenance of air-tight joints is dicult, the employment of air under pressure above atmospheric pressure results in thel escape of pulverized material through such joints, and hence in the operation of the construction of apparatus shown and described in said application, the flow of currents. of air into and from by maintaining within such chamber and at the discharge outlet a pressure below atmospheric pressure. This is effected by connecting the outlet from the chamber to an exhaust fan or pump,A and hence the pulverized material Will pass through the pump or fan, which is in many cases undesirable.`

The invention described herein relates to a construction of pulverizing mill permitting of the introduction at the inner periphery of the revoluble ;hell, of streams or jets of a uid, as for example, air, at a pressure above atmospheric pressure, the circulation of the fluid within the shell andv its escape therefrom, without a liability of the escape of fine material except through an outlet provided for that purpose. The

1922. seriai No. 573,905.

a part of this specification, Fig. 1 is a sectional elevation of a pulverizing mill em-v bodymg improvements claimed herein, the plane of section being coincident with the axis of the mill'; Fig. '2 is an elevation of a portion ofthe discharge screen or plate; Fig. 3 is a side eleva-tion of the annular 11ners as viewed fromthe exterior; Fig. 4 is a lateral cross-section of the sa-me; Fig. 5 is a longitudinal cross-section of the same showing the interior;-Fig.,6 is a longitudinal cross-section showing modification of the form shown in Fig. l; Fig. 7 is aj portion and an end elevation of the end plate 11b as 'shown in Fig. 6;-l Fig. 8 is a sectional elevation of a modified form of that shown in Fig. '1 showing the application of distributor head 15e toany open end type of ball mill or pulverizer.,

In the practice of the invention the drum in which reduction is effected consists of a cylindrical casing 1 having one end closed by a head 2 which 'is protected against abrasion by end liners 2a, and having a hollow-trunnion 3 through which material to be reduced is fed into the drum. Provision should be made for preventing the escape of fluid from the drum through the trunnion through which fuell is fed to the drum. l' hile other means may be employed to prevent the escape of fluid, the construction shown has been found effective and consists of a positively driven feeder screw 4, arranged in the hollow trunnion to which material is supplied from a hopper in such quantity as to maintain the trunnion fully charged. At its opposite end the casing 1 which is preferably made of sheet metal, has secured thereto a ring or tire 5 adapted to ride on rollers 6 during the rotation of the drum by the Ipower driven pinion 7 engaging "the annular toothed member secured` to the' constructed as to form in connection with the casing a plurality of passages l0. rlhe annular liners are retained in lsuch relation to each other by intermeshing keys 10a that continuous passages are formed from end to ese passages are closed end of the drum. Th at one end .by the' head 2. `The annular liners are held vwithin the drum by a lslotted head or grating 1l secured to the casing l and having openings 12 adjacent to the periphery of the head *and adapted, when the head is in position, to register with the passages 10 in the liners.

As it is desired thaft the fluid should escape from the passages 10 into the interior of the drum in directions approximately at right angles to the radii ofthe drum, the interior walls of the liners have approximately radial portions 13 (see Figs. 3 and 4) through which are formed perforations 14 so that the fluid will flow around the iiiterior of the drum at an angle to the radii of the drum.

The fluid enters a Stationary. `distributorhead A, through an opening controlled by valve 28 and flows outwardly into an annular chamber 1,6 formed by an outer hood 17 and an inner hood 21 having their), inner ends securedV respectively to the casi g and the slotted head or grating 11 as shown in Fig. 1. From this annular chamber the -a'ir flows through ports 12 along passageslO in the liners and through perforations 14 into the drum. Adjacent to its inner periphery the outer end of the hoodv 17 is provided with an 'annular surface 18 with which the inner end of the distributor head A forms an lhermetic joint and to this end a packing ring 19 is arranged at the inner end of the distributor head A, said ring being pressed against the surface 18 by springs 20.

In the construction shown in Fig. 1 the inner portion of the head 11 is perforated as at 11a and the conical hood 21 is attached thereto, .the line of attachment being intermediate the'ports 12 and the slots 11a. This hood extends from the head or grating 11 to the inner end of the outlet passage 25 in the distributorhead A and forms a chamber 23 into which the fluid carrying the fine particles enters after passing through the slotted head or grating.

In order to vprevent from accumulating in the circumferential portion of the inner chamber 23, lifting ribs or vanes 22 may be so attached to the inner surfaces of the hood 21 that asI the drum revolves, pulverized material will be carried up and dropped at such points that it will enter the stream of fluid passing through the chambers 23.

As is well known in the art, the rate of flow 'of fluid through the drum and the charge therein should be regulated in accordance with the grade or degree of fineness of the material to be removed. The rate of flow being approximately inversely proportional to the finene of the material to be removed.

It will sometimes occur, when the rate of flow is regulated to remove a particle of the desired fineness from theI drum, that such rate will not be sufficient to carry the pulverized material to the desired point outpulverized material alitalia i side the drum nor sufficient when fuel is being pulverized to effect complete combustion of the fuel. And further, it is not practically possible to so regula-te the rate of flow of fluid as to remove from the drum only material of specific jineness. Some coarser material will always be present in the material discharged from the pulverizer. If the presence of this small amount of coarser material is found to be detrimental in the finished product, the fluid l carrying the material from the drum is passed through a separator or classifier 15aA immediately after leaving the pulverizer which device serves to separate or classifythe larger particles of material from the fine, and from the fluid which passes onward with the fine particles. The coa-rser particles when so removed may be returned to the pulverizer for 4subsequent further reduction in size until sufficiently small to pass through the separator with the air or fluid as material of suitable fineness. As it is not practicable to pass fluid at a sufficient rate through the drum to effect separation or classification nor to carry the material forward'from the drum nor ,to effect complete combustion, additional fluid for either of or all of these co-nditions is admitted to the chamber 23 through ports 24: in the hood 21, permitting fluid under pressurel to flow from the chamber 16 into the chamber 23. These ports are preferably located adjacent to the head or grating 11, and when so located 4the inflowing stream of air will'. supplement the action of the vanes 22 in preventing an accumulation of fine material in the'outer portion of the chamber 23.

In case the fluid flowing Athrough the drum and entering 4through the ports '24 is not sufficient to effect classification, to carr forward the material, or effect desired com ustion, additionalfluid may be admit'- `ted to the stream of fluid and material paing from the discharge passage 25, through the passage 27 in the `distributing head and controlled by valve It is characteristic of the improvement described and claimed hereinthat the fluid employed for theremoval of fine material from the pulverizer enters the drum in a direction substantially parallel with the axis of thev drum, such .fluid being preferably divided into a plurality of. streams. These streams are preferably subdivided into a plurality of jets having an initial direction at, an angle to radii of the drum. Within the drum the direction of movement of the fluid changes and the fluid laden with fine particlesl flows from the drum at the same end at which it enters but at points within the points of entry.

In order to maintain a separation of the infr-owing from the utflowing liquid, a-distributing head A having inlet and discharge passages 15 and 25, is employed The discharge passage has its inner end substan= tiallycentral of the head so asto be in alinement with the outlet opening of the chambelr 23. At its inner end the inlet passage is annular and 'connects with the annular chamber 16 from which the fluid passes into the drum.

In the form shown in Figs; 6 and 7 provision is made for the entrance of the air or fluid in a similar manner to that hereinbefore described 'and illustrated by Figures 1, 2, 3, 4, and', but provision is made for the escape of fluid and fine material carried thereby through the perforated tube 30 in the manner described in application Serial No. 539,417 of February 27, 1922. Said tube is so supported that it-s axis will coincide approximately with the axis of the drum. The outer end of the tube extends' through thesolid head 11b as shown in Fig. 7 and is in alinement with the outlet passage 25 of the distributing chamber. The outer end of the perforated tube 30 and end of the outlet passage 25 are separated for the admission of additional fluid to the stream of fluid and pulverized material flowing from the tube 30 for thesame purposes that fluid is admitted through ports 24 in the form shown in Fig. 1. The flow of fluid through this opening is regulated by means of a movable collar or flange 31 sliding upon the outside of the wall of the outlet passage 25 and'adjusted by means of hand crank 32 acting upon pins 33 and 34.

The pulverizer shown in Figs. 6'and 7 formed and constructed as hereinbefore described in Fig. 1, except that the head 11c is made solid or imperforate. This head is protected on the interior against abrasion with`liners as at 2, Fig. 1, and is provided with peripheral openings 12. Attached to the outer side of the head 11c are a series of radial vanes 42 spaced. to form a number of channels 43 radiating from the center and corresponding in number to the peripheral openings 12. Covering these channels and coming into close contact with the outer edges of the vanes is an outer hood 44 which is attached to the rotating drum in the same manner as is the hood 17, Fig. 1. At the outer end of this hood 44 an opening is formed which .registers with the inner open end of the distributor head A. -Fluid enters the distributor-head at 35, passes through channel 38 on one side of shutter 37, enters channels 43, passes through opening 12 in end head 11C, through fluid channels 10, perforations 14, into the drum` passing through the 'drum interior where' it becomes laden with fine material and leaving drum on opposite side through perforations 14, channels 10, ports 12, channels 43, and leaving distributor head through enters,

the inner the channel 39 on opposite side -of the shut-` ter 37 from that in which the air or fluid thence out through the outlet port 36.

As shown in Fig. 8 the improved distributor can be so combined with the type or construction of ball mill that the Huid will enter one end of the drum adjacent to its periphery and circulating through the drum and will flow therefrom carrying pulverized material through openings in the head at the same end it entered, the discharge openings being arranged'within the inlet ports.

As shown in Fig. 8 a rotating drum 1a protected on its interior by hard metal liners, and equipped at one end with any suitable feeding device, is provided at the end opposite the feeding mechanism with a screen or grating 111L attached to casing la. Attached to the periphery of the casing at the discharge end is an outer hood 17 a which is provided on its inner *side with a series of radial vanes 45 forming a series of pockets having their inner ends open for the reception of pulverized material which may drop from the stream of fluid and pulverized ma: terial flowing from the drum. As the drum rotates, the material will drop from the pockets into the stream flowing from the drum. v

Means such as are shown in Fig. 1 at 18, A19, and 20, are employed for forming a tight joint between the outerend of the cone 17a which rotates with the drum and the inner end of the stationary distributor C'.

An inner cone 21a is attached.l to the distributor head C at the inner end of the outlet p-assage 25 in an adjustable manner, as indicated. This cone flares out peripherally leaving an annular opening around its entire lcircumference between` its inner edge and they face of the screen or grating 11a.

In. operation, the lower passage 15c of the distributor head, passes through the chamber 16a formed by the cones 17 1 and 21a, sweeping the pockets between the radial ribs 45 and enters the drum through the ports 12b. Within the drum the fluid vwill move inwardly towards the axis of the drum pic-king up the pulverized material and escaping through the openings in the screen or grating 11a and will How through the cone 21a and the discharge passage 25 in the distributor head. Whatever additional fluid is requiredfor the inward movement of the material for effecting classification or combustion, will be supplied from the chamber 16a, such fluid passing from the chamber through the annular opening between the cone 21a and the screen or grating.

It will be observed that the chambers or passages through which the fluid passes after picking up pulverized material, are surrounded by fluid of a higher pressure than the fluid employed enters at lea the portions carrying the pulverized material, and hence there Will not be any escape of pulverized material through loose or defective joints but the fluid, free from pulverizedmaterial, WillfloW inwardly through such joints.

drum in which .It will be understood that although it -is preferred to\force the fluid through the mill by a fan, blower, or pump, connected to the inlet passage of the distributing head, the carrying fluid-may be drawn through the mill.

l claim herein as my invention:

1. The method herein described Vof removing pulverized material which consists in causing fluid to enter the drum in which pulverizati'on is effected at points adjacent to the periphery of the drum and in a direction substantially parallel with the axis of the drum, and to flow from the drum in a reversed direction.

2. The method herein describedI for removing pulverized material which consists in causing fluid to flow into one end of the drum in which pulverization is effectedl at points adjacent to the periphery of the drum and in a direction substantiallyparallel With the axis of the drum, and'to flow from the same end of the drum at points Within thel points of entry.

3. The method herein, described of removing pulverized material which consists in causing fluid to flouT into one end of the -pulverization is effected in annularly arranged jets or streams and to flow from the same end of the drum, such outflow being along theI annular space enclosed by the inflovving streams.

4. The method herein --described of operating a pulverizing mill utilizing the flow of a fluid for removing fine particles from the mill, which consists in surrounding the portionsof the fluid carrying'r the fine particles with fluid at a higher pressure than the dust laden portions.

5. A pulverizing mill having a drum having longitudinal passages adjacent to its periphery and ain anniilar chamber communicating with such passages and provided with outlet openings arranged to discharge into the space Within the annular chamber in combination with a head having passages .communicating respectively with the annular chamber and with the space enclosed thereby. v

6. A pulverizing mill having a drum provided vvith a series of longitudinal passages,

adjacent to its periphery and having perforated Walls in combination With spaced an- -nular Walls or hoods so supported at one end of the drum as to form an annular chamber communicating with the passages, a head for the drum having openings therethrough permitting ofv the flow of fluid into the chamber formed by the inner Wall `stationary orvhood, a distributing head provided with passages communicating respectively with the annular chamber and with the chamber formed by the inner annular Wall or hood.

7 A pulverizing mill having a drum provided with a series of longitudinal passagesv arranged adjacent to its periphery and having yperforated walls in combination with spaced annular walls or hoods so supported at one end of the drum as to form an annular chamber communicating with the passages,

head having inlet and outlet passages communicating respectively with the annular chamber and with the chamber formed by the inner annular Wall or hood.

8. A pulverizing mill having a rotating drum provided with longitudinal passages arranged adjacent to its periphery and having` perforated Walls in combination With spaced annular Walls or hoods so secured to the one end of the drum as to form between an annular chamber communicating With the passages,.a head for the vdrum-having openings permitting the How of fluid from the drum into the chamber formed by the inner Wall or hood, vanes carried by the inner hood for carrying pulverized material up to a point Where it Will drop into the fluid flowing' into the inner an'nular Wall or hood, a distributing head having inlet and outlet passagescommunicating respectively With the annular chamber and with the chamber formed by the inner annular Wall or hood.

9. A pulverizingmill having a rotating drum in combination-With annular Walls or hoods so supported at one end of the drum as to form with the head of the drum an annular inlet chamber and an inner `discharge chamber communicating with the drum, a v

distributing head having inlet and. outlet passages communicating respectively with the annular inlet chamber and the discharge outlet chamber formed by the inner annular Wall or hood,andaclassifier connected to the discharge `passage in the head.

10. A pulverizing mill having a rotating drum in combination with annular Walls or hoods so supported at one end of the drum as to form With-the head of the drum an annular inlet' 'chamber and an inner discharge chamber communicating With -the drum, a distributing head having inlet and outlet passages communicating with -the annular inlet chamber land the discharge or outlet ychamber formed by the inner hood, a classifluid tothe fluid Vflowing from the drum.

l1. A pulverizing mill having a rotating drum in combination with annular walls or hoods so supported at one end ofthe drum as to form with the head of the drum an annular'inlet chamber and an innerdischarge ychamber,communicating with the drum, a

distributing head having inlet and outlet passages communicating respectively With the annular inlet chamber and the discharge or outlet chamber formed by the inner hood said chambers being connected by ports or openings permitting the flow of fiuid from the inlet chamber to the discharge chamber, and a. classifier connected to the discharge passage in the head.

l2. A pulverizing mill having a rotating drum in combination with conical hoods so supported as to form With the head of the drum an annular inlet chamber and an outlet chamber, a classifier and stationary distributing head provided With passages communicating respectively With the annular inlet chamber, the outlet chamber and the classifier. y

13. A drum for a pulverizing mill having in combination a casing and a plurality of annulgr transversely grooved liners fitting within the casing and adapted to form with the casing, passages, extending longitudinally of the drum, said liners having perforations for the fioW of Huid into the drum.

14. A pulverizing mill having a drum provided with longitudinal passages adjacent to its periphery in combination with walls arranged at the end of the drum to form an -annula-r chamber communicating With said passage and a central chamber communicating with the drum, a head having passages communicating respectively with the annular and central chambers.

15. A pulverizer in combination with a head interposed between the fluid supply and the mill and provided with a passage for the infiowof air, a passage for the flow of dust laden fluid from the mill, and a by-pass communicating with the supply and the outlet passage, and means for regulating the flow of fluid through the by-pass.

16. A rotatable pulverizing mill in combination with a stationary distributing head provided with a passage for conducting fiuid to the mill and with a passage for conducting fiuid discharged from the mill, and a passage for conducting clean fluid to the discharge passage.

17. A rotatable puverizing mill in combination with a stationary head, provided With a passage for conducting fiuid flowing from the mill and means for maintaining outside the joint between the head and mill a Huid .under pressure higher than that fiowing from the mill.

In testimony whereof, I have hereunto set my hand.

RALPH E. H. POMER'OY; 

